Yes the outermost layer of the tooth wears off with time. This can be due to friction from hard brushing, abrasions due to coarse toothpaste or eating highly acidic or sour foods like pickles , lemons etc.. Enamel can also wear off if the patient has severe acidity which causes acid regurgitation.
Next Steps
Evaluate the cause of enamel abrasion/erosion
Health Tips
Always use soft or medium bristled toothbrush and brush in a small circular motion instead of horizontal or vertical brushing.